Forced air heater

ABSTRACT

There is a disclosure herein a portable forced air heater including an outer housing containing a combustion chamber and a blower motor mounted upstream of the combustion chamber. An airscoop and nozzle assembly are mounted at the inlet end of the combustion chamber. The construction of the combustion chamber and burner components allows improved performance and relatively easy assembly and disassembly.

451 nan 29, W12

United Silos atom Dent ct al.

[54] FORCED AER HEATER FOREIGN PATENTS OR APPLICATIONS Inventors: Charles E Dem, p ld A. 929,433 6/1963 GreatBritain........................263/19A Vaughn, Ontario, both of Calif.

[73] Assignee: Scheu Manufacturing Company, Upland, Primary ExamineFJohn lcamby Calif. Attorney-Lyon & Lyon ABSTRACT [22] Filed: May 13, I970 21 Appl. No.: 36,707

There is a disclosure herein a portable forced air heater including an outer housing containing a combustion chamber and a blower motor mounted upstream of the combustion [52] US. A, 126/110 C 1 Ciin...........................................................F23l chamber A ai -scoop and nozzle assembly are mounted at the [58] new of Search A; 126/1 10 l 10 D inlet end of the combustion chamber. The construction of the References Cited combustion chamber and burner components allows im- UNITED STATES PATENTS proved performance and relatively easy assembly and disassembly.

ShermanI.............................263/l9 A 11 Claims, 112 Drawing Figures Patented Feb. 29, 1972 3,645,512

3 Sheets-Sheet 5 INVCNTORS. (71646665 6. DEA/7' DON/4L0 A VAUGHN FORCED AIR HEATER This invention relates to forced air heaters of the type disclosed in US. Pat. No. 3,494,599, the disclosure of which is incorporated herein by reference, and which is assigned to the assignee of the present application.

The present invention relates particularly to a relatively small and compact portable forced air heater for providing a high heat output. Various types of heaters and forced air heaters have been devised in the past. Typical heaters having a high heat output have been relatively large and bulky and sometimes have lacked suitable safety features. The heater disclosed in said patent represents a substantial improvement over such prior heaters. TI-Ie present heater involves further improvements in the provision of a smaller and more compact heater which is of modular construction and relatively easy to service, and which also incorporates several novel structural features.

Accordingly, it is a principal object of this invention to provide a new portable forced air heater.

It is an additional object of this invention to provide a compact and lightweight forced air heater of modular construction which may be readily disassembled and reassembled for service.

Another object of this invention is to provide a portable forced air heater having a novel structure.

These and other objects and features of the present invention will become better understood through a consideration of the following description taken in conjunction with the drawings in which:

FIG. 1 is a side elevational view, partially in section, of a portable heater according to the present invention;

FIG. 2 is a cross-sectional view of the nozzle assembly of the heater;

FIG. 3 is an exhaust end view of the heater taken along a line 33 of FIG. 1;

FIG. 4 is a combustion chamber inlet view taken along a line 4-4 of FIG. 1',

FIG. 5 is a perspective view of the intake cover of the com bustion chamber of the heater;

FIG. 6 is a perspective view illustrating components of the nozzle assembly;

FIGS. 70 and 7b are perspective views illustrating an airscoop employed at the intake of the combustion chamber;

FIG. 8 is a fragmentary cross-sectional view of the intake of the combustion chamber;

FIG. 9 is a view within the combustion chamber taken along a line 9-9 ofFlG. 8;

FIG. 10 is an interior view of the combustion chamber taken along a line ll010 of FIG. 8; and

FIG. 11 is a fragmentary cross-sectional view of the airscoop and nozzle at the intake of the combustion chamber taken along a line 11-11 of FIG. 8.

Turning now to the drawings, an exemplary embodiment of a forced air heater according to the concepts of the present invention includes a housing 10 formed of tubular metal sections or shells 11 and 12, and a base section 13 to which the housing 10 is secured. The base section 13 may include various control components, such as electrical and gas control devices similar to those disclosed in said US Pat. No. 3,494,599. Such components serve to control a motor and burner ofthe heater.

A motor 14 is mounted within the shell 11, and a suitable fan blade 15 is mounted on the shaft of the motor. An inlet grill or screen 16 is provided to prevent large objects from being sucked into the heater. As will be apparent to those skilled in the art, the motor 14 and blade 15 serve to provide combustion air.

A combustion chamber 20, which may be formed of stainless steel or the like, is mounted within an outer downstream shell 12. A liner or heat shield 21 is mounted coaxially with respect to the combustion chamber 20 between the combustion chamber and the shell 12 by means of suitable brackets and screw fasteners as best seen in FIGS. 1, 9 and 10. These brackets provide spacing between the combustion chamber, liner and outer shell, a typical spacing between each being three-eighths inch. This results in an annular airspace between the shell 12 and the liner 21 which aids in keeping the exterior of the heater cool, and a similar airspace between the liner 2! and combustion chamber 211 which both aids in keeping the exterior of the heater cool as well as provides secondary combustion air which is introduced into louvers 23 in the wall of the combustion chamber 20. However, it is not necessary to employ the louvers 23.

Considering the combustion chamber 20 in more detail, the same includes a cylindrical wall 24 having the louvers 23 therein. A cover 25 as seen in FIGS. 1 and 5 is provided at the inlet end of the combustion chamber 20, and the cover is provided with an intake opening 26 as best seen in FIGS. 5, 8, 9 and 11. An outlet baffle 28 as best seen in FIGS. 1 and 3 is secured to the outlet end of the combustion chamber 20. The outlet baffle 28 includes an outlet opening 29 which is flared inwardly, and a plurality of holes 30. Typically, the opening 29 is 3 3/8 inches in diameter, and i /zinch diameter holes 30 are provided at a radius of 2%inches. The baffle 23 may be formed from stainless steel, or other suitable materials.

Turning again to the intake end of the: combustion chamber 20, the same is provided with an airscoop 34, nozzle assembly 35, spark plug 36, flame sensor 37, and a high limit sensor 38 as best seen in FIGS. 1 and 4. The airscoop 34 serves to scoop the air provided by the blower motor and properly direct the air through the intake opening 26 of the: combustion chamber 20 for combustion of fuel emanating from the nozzle 35. The spark plug 36 enables automatic ignition of the fuel, the flame sensor 37 detects the existence of a suitable flame, and the high limit detector 33 detects the existence of an overheating condition, all as will be apparent to those skilled in the art.

Turning first to the airscoop 34, the same includes a plurality of airscoop members 410 through 43 each terminating in an arcuate end, such as an end 44 of the member 40. Each of the members 46 through 43 is alike and includes three flanges. lnasmuch as these members are alike, only the member 49 will be described in detail, which includes a flange 45 which is secured to the intake cover 25 of the combustion chamber 20, a flange 46 which is secured to the liner 21, and a flange 47 which is secured to a nozzle mounting plate 48. The mounting plate 48 includes a configured opening 19 therein, preferably hexagonal, and a cutout portion 51). The nozzle assembly 35 is secured to the mounting plate 48 in the manner illustrated in FIGS. 2, 6 and 8.

The nozzle assembly 35 includes a nozzle 52 preferably formed of hexagonal stock, such as %-inch hex aluminum, having a passageway 53 as best seen in FIG. 2 communicating with outlet orifices 54. As will be apparent to those skilled in the art, a fuel line 55 is suitably connected to the end 56 of the nozzle 52. A groove 58 is provided in the nozzle for receiving a retaining clip or ring 59. A shoulder 60 of the hex stock remains which fits with the hex opening 49 in the mounting plate 48. A nut 61 secures the nozzle 52 to the mounting plate 48. A flame spreader plate 63 is secured to the forward end of the nozzle 52 by means of a screw fastener at.

The configured opening 49 in the mounting plate 48 as well as the configured periphery of the shoulder 60 of the nozzle 52 provides a predetermined and positive alignment of the outlet orifices 54 of the nozzle 52 with respect to the spark plug 36. In this regard, note should be made of FIG. 9 which illustrates the orientation of the orifices 54 with respect to the position of the spark plug 36. This nozzle assembly 35 is relatively inexpensive to machine, provides positive positioning of the orifices 54 with respect to the spark plug 36 for enabling proper ignition of the fuel, and the same is easy to disassemble and assemble for servicing. Positioning of the orifices 54 with respect to the spark plug 36 is relatively important as will be apparent to those skilled in the art. The cutout 5E1 ensures proper orientation of the mounting plate 48 with respect to the spark plug 36, and the opening 49 and shoulder 60 ensure accurate alignment of the orifices 54 to enable proper ignition. This relatively simple arrangement ensures proper initial assembly and alignment of the nozzle assembly, as well as proper alignment thereof after disassembly for servicing. Although the opening 49 ans shoulder 60 are shown as hexagonal, other suitable configurations can be used.

Turning again to the construction of combustion chamber 20, it should be noted that the relatively small intake opening 26 allows the flame from the nozzle assembly 35 to extend forward because of the substantial airflow therethrough even with a certain amount of blockage at the inlet grill 16. The outlet baffle 28 serves to contain the flames, and keeps the flames from belching out too far from the exhaust end of the heater, and helps in obtaining complete combustion. The outlet baffle 28 allows the combustion chamber to be shorter thereby enabling a relatively compact heater to be constructed. The use of a combustion chamber 20 within a liner 21, and all within an outer shell 12 allows a heater to be provided which has a cooler exterior temperature. A relatively compact heater of the nature described herein weighing approximately thirty two pounds can provide 150,000 B.t.u. output. Natural gas or propane typically are used with heaters of this nature.

The flame sensor 37 includes a probe 68 which extends through an aperture 69 in the intake cover 25 of the combustion chamber 20 in a position to best sense the flame from the nozzle assembly. Similarly, the high limit sensor 38 is mounted on a suitable bracket 70 behind an aperture 71 in the cover 25, and the location thereof illustrated enables proper high limit sensing while not degrading the burning characteristics of the heater.

The present embodiment of this invention is to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein.

What is claimed is:

l. A portable heater comprising a housing forming a shell having an inlet and an outlet,

a combustion chamber positioned within said shell between said inlet and outlet, said combustion chamber having inlet and outlet ends, said outlet end of said combustion chamber having a baffle member secured thereto, said baffle member having a central opening and a plurality of openings disposed around said central opening, and

noule means disposed within said shell and extending into said inlet end of said combustion chamber.

2. A heater as in claim 1 wherein said central opening of said baffle member includes an inturned flange, and said combustion chamber includes a substantially cylindrical wall extending between said inlet and outlet ends thereof.

3. A heat as in claim 1 wherein airscoop means is affixed to the inlet end of said combustion chamber for deflecting air through said inlet end and about said nozzle means, said scoop means including means for supporting said nozzle means at the inlet end of said combustion chamber.

4. A heater as in claim 1 wherein said shell is substantially cylindrical and said combustion chamber includes a body which is substantially cylindrical, and

a liner mounted within said shell about said combustion chamber, said body of said combustion chamber, said liner and said shell forming an airspace surrounding said body and an air space surrounding said liner.

5. A heater as in claim 1 including bracket means coupling said nozzle means to said combustion chamber,

ignition means disposed in said combustion chamber for igniting fuel from said nozzle means, and

said nozzle means comprises a nozzle having a plurality of orifices, and having a configured peripheral portion mating with a configured opening in said bracket means for facilitating orientation of said orifices with respect to said ignition means. 6. A portable forced air heater comprising a housing forming a shell having an inlet and an outlet, 5 fan means coupled with said shell for supplying air through said shell toward said outlet,

a combustion chamber positioned within said shell downstream of said fan means for receiving air from said fan means, said combustion chamber having constricted inlet and outlet ends, said outlet end comprising a baffle member secured to said chamber, said baffle member having a central opening and a plurality of openings disposed about said central openings, said baffle member having a flange at said central opening extending into said chamber,

nozzle means disposed in said shell and extending into said inlet end of said combustion chamber for supplying fuel into the combustion chamber, and

liner means mounted about said combustion chamber between the chamber and said shell.

7. A heater as in claim 6 wherein said combustion chamber has a substantially cylindrical wall extending between said inlet and outlet ends, said cylindrical wall having apertures therein for admitting air into said combustion chamber.

8. A heater as in claim 6 wherein said combustion chamber comprises a substantially cylindrical wall with an inlet cover, and with an outlet cover forming said baffle member, said inlet cover having an aperture therein, and bracket means mounting temperature sensitive means adjacent said aperture in said inlet cover for sensing a predetermined temperature within said combustion chamber.

9. A nozzle assembly for use with a portable forced air heater employing a combustion chamber having an inlet end to which said nozzle assembly and ignition means are coupled, said assembly comprising bracket means for mounting said assembly in a predetermined relationship with respect to said ignition means, said bracket means having a conflgurated opening therein,

an elongated nozzle having a passageway therein terminating in a plurality of fuel outlet orifices radiating from the longitudinal axis of said nozzle, said nozzle having at least a configured peripheral portion mating with the configured opening in said bracket means for facilitating orientation of said orifices with respect to said ignition means, and

a flame spreader plate coupled with the downstream end of said nozzle downstream of said orifices.

10. A portable forced air heater comprising a housing having an inlet and an outlet,

fan means coupled with said housing for supplying air through said housing toward said outlet,

combustion chamber means positioned within said housing for receiving air from said fan means, said combustion chamber means comprising a substantially cylindrical shell having an inlet cover and an outlet baffle, said inlet cover having an opening therein and said outlet baffle having a central opening therein and a plurality of apertures disposed about the central opening thereof,

ignition means coupled with said inlet cover of said combustion chamber means for igniting fuel in said chamber,

nozzle means mounted in said housing and extending into said opening in said inlet cover of said combustion chamber means for supplying fuel into said combustion chamber, said nozzle having a plurality of fuel outlet orifices radiating from the longitudinal axis of the nozzle and having at least a configured peripheral portion mating with bracket means for facilitating positioning of said nozzle in said inlet cover with respect to said ignition means, and a flame spreader plate coupled with the downstream end of said nozzle, and

nozzle means disposed in said shell and extending through an opening forming said constricted inlet end of said con bustion chamber means and extending into said chamber means for supplying fuel into the combustion chamber means, said nozzle means comprising an elongated nozzle having a plurality of fuel outlet orifices radiating from the longitudinal axis of the nozzle and a flame spreader plate coupled with the downstream end of said nozzle, the downstream end of said nozzle with said orifices being positioned within said combustion chamber means downstream of the constricted inlet end of said cornbustion chamber means. 

1. A portable heater comprising a housing forming a shell having an inlet and an outlet, a combustion chamber positioned within said shell between said inlet and outlet, said combustion chamber having inlet and outlet ends, said outlet end of said combustion chamber having a baffle member secured thereto, said baffle member having a central opening and a plurality of openings disposed around said central opening, and nozzle means disposed within said shell and extending into said inlet end of said combustion chamber.
 2. A heater as in claim 1 wherein said central opening of said baffle member includes an inturned flange, and said combustion chamber includes a substantially cylindrical wall extending between said inlet and outlet ends thereof.
 3. A heat as in claim 1 wherein airscoop means is affixed to the inlet end of said combustion chamber for deflecting air through said inlet end and about said nozzle means, said scoop means including means for supporting said nozzle means at the inlet end of said combustion chamber.
 4. A heater as in claim 1 wherein said shell is substantially cylindrical and said combustion chamber includes a body which is substantially cylindrical, and a liner mounted within said shell about said combustion chamber, said body of said combustion chamber, said liner and said shell forming an airspace surrounding said body and an air space surrounding said liner.
 5. A heater as in claim 1 including bracket means coupling said nozzle means to said combustion chamber, ignition means disposed in said combustion chamber for igniting fuel from said nozzle means, and said nozzle means comprises a nozzle having a plurality of orifices, and having a configured peripheral portion mating with a configured opening in said bracket means for facilitating orientation of said orifices with respect to said ignition means.
 6. A portable forced air heater comprising a housing forming a shell having an inlet and an outlet, fan means coupled with said shell for supplying air through said shell toward said outlet, a combustion chamber positioned within said shell downstream of said fan means for receiving air from said fan means, said combustion chamber having constricted inlet and outlet ends, said outlet end comprising a baffle member secured to said chamber, said baffle member having a central opening and a plurality of openings disposed about said central openings, said baffle member having a flange at said central opening extending into said chamber, nozzle means disposed in said shell and extending into said inlet end of said combustion chamber for supplying fuel into the combustion chamber, and liner means mounted about said combustion chamber between the chamber and said shell.
 7. A heater as in claim 6 wherein said combustion chamber has a substantially cylindrical wall extending between said inlet and outlet ends, said cylindrical wall having apertures therein for admitting air into said combustion chamber.
 8. A heater as in claim 6 wherein said combustion chamber comprises a substantially cylindrical wall with an inlet cover, and with an outlet cover forming said baffle member, said inlet cover having an aperture therein, and bracket means mounting temperature sensitive means adjacent said aperture in said inlet cover for sensing a predetermined temperature within said combustion chamber.
 9. A nozzle assembly for use with a portable forced air heater employing a combustion chamber having an inlet end to which said nozzle assembly and ignition means are coupled, said assembly comprising bracket means for mounting said assembly in a predetermined relationship with respect to said ignition means, said bracket means having a configurated opening therein, an elongated nozzle having a passageway therein terminating in a plurality of fuel outlet orifices radiating from the longitudinal axis of said nozzle, said nozzle having at least a configured peripheral portion mating with the configured opening in said bracket means for facilitating orientation of said orifices with respect to said ignition means, and a flame spreader plate coupled with the downstream end of said nozzle downstream of said orifices.
 10. A portable forced air heater comprising a housing having an inlet and an outlet, fan means coupled with said housing for supplying air through said housing toward said outlet, combustion chamber means positioned within said housing for receiving air from said fan means, said combustion chamber means comprising a substantially cylindrical shell having an inlet cover and an outlet baffle, said inlet cover having an opening therein and said outlet baffle having a central opening therein and a plurality of apertures disposed aboUt the central opening thereof, ignition means coupled with said inlet cover of said combustion chamber means for igniting fuel in said chamber, nozzle means mounted in said housing and extending into said opening in said inlet cover of said combustion chamber means for supplying fuel into said combustion chamber, said nozzle having a plurality of fuel outlet orifices radiating from the longitudinal axis of the nozzle and having at least a configured peripheral portion mating with bracket means for facilitating positioning of said nozzle in said inlet cover with respect to said ignition means, and a flame spreader plate coupled with the downstream end of said nozzle, and air deflecting means mounting downstream of said fan means for deflecting air into said opening in said inlet cover of said combustion chamber means.
 11. A portable forced air heater comprising housing means forming a shell having an inlet and outlet, fan means disposed for supplying air through said shell toward said outlet, combustion chamber means positioned within said shell downstream of said fan means for receiving air from said fan means, said combustion chamber means having constricted inlet and outlet ends, said outlet end comprising a baffle member having a plurality of openings therethrough, and nozzle means disposed in said shell and extending through an opening forming said constricted inlet end of said combustion chamber means and extending into said chamber means for supplying fuel into the combustion chamber means, said nozzle means comprising an elongated nozzle having a plurality of fuel outlet orifices radiating from the longitudinal axis of the nozzle and a flame spreader plate coupled with the downstream end of said nozzle, the downstream end of said nozzle with said orifices being positioned within said combustion chamber means downstream of the constricted inlet end of said combustion chamber means. 